Increase Photo-realism in Final render
Use a better lighting, possibly with an HDRI in your scene. A part of the reason why the textures look unreal is that they are completely grey and flat.
Use image textures and include slight bump mapping for things like the fake leather and so on. What I like to do is get, for example, a leather texture that might be any colour just for the texture, then combine the colour input with a MixRGB node to what I want.